imposing a blockade on the government offices, but later eased it after contacts between opposition leaders and Arab diplomats, according to a senior opposition source.

On Saturday, hundreds of supporters of Hezbollah and its allies - the Shia Muslim Amal Movement and the Free Patriotic Movement of Christian opposition leader Michel Aoun - were stretched out on the pavement wrapped in blankets or huddled around camp fires keeping warm in the morning chill.

Scores of soldiers have cordoned off the government offices in Beirut with barbed wire and metal barriers.

Saudi backing

King Abdullah of Saudi Arabia, an Arab diplomatic heavyweight, told Fouad Siniora and ministers with him in the government headquarters that his country supported them, Siniora's office said.

Saudi Arabia would not accept any deterioration in the security situation, Abdullah said during a phone call.

Siniora's government is ranged against a Hezbollah-led political alliance

Although the dispute is political, many Lebanese fear the situation could spark sectarian violence. Tension between Sunnis and Shias is high, as is bad feeling between Christians who support leaders allied to the rival camps.

Participants in Friday's rally created a sea of Lebanese flags downtown that spilled onto the surrounding streets amid the deafening sound of Lebanese nationalist songs.

Many chanted slogans demanding that Siniora quit.

In response, Sunni Muslim leader Saad al-Hariri, who backs Siniora, told Al Hurra television late on Friday: "No matter how long they stay in the street ... this will not bring down the government ..."

Aoun speech

In a speech during the protest, Michel Aoun, the leader of the Free Patriotic Movement party, said: "I call on the prime minister and his ministers to quit."

Organisers said the protesters put up tents on main roads leading to the Grand Serail building to force the resignation of Siniora, who was inside his offices with a group of cabinet ministers.

"These are not Hezbollah supporters, they are Lebanese from every sect," Al Jazeera's Rula Amin said.

The call for peaceful street action came after a statements by Hassan Nasrallah, leader of Hezbollah, and other leaders.

"We appeal to all Lebanese, from every region and political movement, to take part in a peaceful and civilised demonstration on Friday to rid us of an incapable government that has failed in its mission," he said.

Opposition supporters say they are not going anywhere soon

The Lebanese military has instructions to maintain order and not take sides during the protest and open-ended sit-in.

Tents, food, medical supplies and electrical generators are being distributed for what is expected to be a lengthy display of dissatisfaction.

Ibrahim al-Moussaoui, Al-Manar television's editor, said protesters will lay siege till the government is brought down.

"The government has let down the people of Lebanon. Demonstrations will continue till the government is brought down, if not then people might resort to civil disobedience."

Walid Jumblatt, a senior pro-government politician, said both the March 14 coalition and the government will face the opposition protest and blockade calmly. "The current crisis in Lebanon can only be solved by dialogue," he said, while rejecting what he called "Syrian-Iranian tutelage".